Lab experiments

Experimental group

• Group in which the conditions are varied and changes measured

Control group

• Group in which the conditions are maintained and changes measured

Independent variable

• Thing that’s being changed

Dependent variable

• Thing that’s being measured (as it depends on what is being changed)

Reliability

:)

2 reasons lab experiments are reliable

1. Ability to specify precise steps and measures taken

   • This allows other researchers to exactly repeat the experiment

2. Detatched method

   • Researcher purely manipulates the variables and records results

     • Personal feelings and opinions have no impact on the outcome or conduct of the experiment

Ethics

Conducting experiments with human beans…:(

3 ethical concerns surrounding lab experiments

1. Lack of ICF

• Difficult to obtain from children and those with disabilities

  • They must understand the nature and purpose of the experiment before partaking

2. Deception

• Misleading people is considered to be wrong, but is sometimes necessary for experiments to prevent the Hawthorne Effect or impression management

3. Harm

• Even if physical harm is not caused, psychological harm can occur, which may lead to physical harm like seizures 

Practicality

:/

3 practical problems with lab experiments

1. Society is complex

• You cannot identify/control every single possible variable that could influence someone

  • E.g. Milgram could not control participant’s free will (they knew they weren’t killing anyone but did it anyway)

2. Cannot be used to study the past

• Cannot control variables acting in the past

3. Difficult to investigate large-scale social phenomena

• E.g. religion, voting patterns

• However, small-scale experiments are less representative (double-edged sword…)

Positivists and lab experiments

• :)

• Due to:

  • Careful control over experimental conditions due to researcher detachment and therefore repeatability

  • Quantitative measure of behaviour

  • Ability to manipulate values

• Can therefore establish cause-and-effect relationships

• They do recognise shortcomings (so may use a comparative method)

  • Small scale = not representative, can’t generalise

Interpretivists and lab experiments

• :(

• Invalid due to artificial situation that creates unnatural behaviour

• Favour field experiments, but just don’t like experiments

Difference to field experiments

• Artificial lab environment

• Subject often aware they’re part of an experiment (therefore possibility of Hawthorne Effect)

Milgram (1974) - explanation

• Group of participants were given a test to conduct on someone tied to an ‘electric chair’ in the other room

• Every time they got an answer wrong, they were instructed to shock them by another actor, who was in the room with them

• This went up to 400V, which they were told would kill the testee

• Actors were actually given a script to read and told to scream/cry/yell in pain with each ‘shock’

• They also cried out things like ‘please stop’

• The actor in the room was reading from a script and could not vary from this

Milgram (1974) - theoretical perspective

• Positivists :)

  • V. replicable due to extensive control over variables

    • Has been done many times, often for game shows

  • Provides quantitative data

Milgram (1974) - ecological validity

• Difficult to prove as the environment it was conducted in is nothing like the real world

Milgram (1974) - ethics

• Consent:

  • Participants gave their consent to do the experiment but did not know what it entailed (were lied to) so did not give their true informed consent in this circumstance

• Deception:

  • Lied about use of electric shocks

• Harm:

  • Participants suffered psychological harm from believing they killed someone, and even if debriefed suffered psychological harm from believing they w/could have killed someone

  • Some participants went on to have seziures, one so severe the experiment had to be stopped 

Milgram (1974) - practicality

• V. expensive

  • Paying the actors

  • Creating the whole set-up with the switches etc. to make it look realistic

  • Hiring the rooms

• Could have the Hawthorne Effect in play

• Can’t control free will

  • People may have known they were never going to be made to kill someone, so would have gone ahead with the switches for the shits ‘n gigs

Harvey and Slatin (1976) - explanation

• Showed 96 teachers 18 photos of children from different class backgrounds

• Asked them to judge the child’s ability

• More experienced teachers (but also all teachers) judged children who appeared to be from lower social classes less favourably

Harvey and Slatin (1976) - usefulness

• Shows teachers label pupils by social class and use said labels to judge student’s potential

Harvey and Slatin (1976) - ethics

• :)

  • Didn’t use real pupils so no harm could come to them and no consent needed

Harvey and Slatin (1976) - theoretical perspective

• Interpretivists :(

  • Quite artificial as didn’t use real pupils so can’t see the true meaning teachers give to the situation

Charkin et al (1975) - explanation

• Made uni students teach a 10/yo boy some content

  • 1/3 were told he was motivated and intelligent

  • 1/3 were told he had poor motiviation and a low IQ

  • 1/3 were told nothing

• Found that students were more encouraging, used more eye contact and more positive body language when told the boy was intelligent

  • However, how does this link to their performance?

Charkin et al (1975) - ethics

• Harm:

  • Used a real boy, so harm could have come to him

• Consent:

  • He’s vulnerable because he’s a child, did he sign an ICF? were safeguarding measures in place as the ‘teachers’ were not real teachers?

Charkin et al (1975) - theoretical perspective

• Intepretivist :(

  • Didn’t use real teachers, so artifical and therefore invalid

Mason (1973) - explanation

• Teachers given pos/neg/neu reports on a pupil

• Then asked to predict the pupil’s end of year attainment by watching a video of them taking a test

  • Found negative reports have a greater impact on teacher expectations than positive ones

Mason (1973) - ethics

• Harm:

  • Didn’t have the teachers actually interact with the pupil, so there was no true impact on their attainment

• Consent:

  • The pupil in the video is still vulnerable, did they know what their video was being used for?